Web feed mechanism for wrapping machines

ABSTRACT

An apparatus for feeding a web of material, such as a plastic film or paper, from a supply roll and for cutting it into sheets of desired length to be used in a package wrapping machine or the like. The apparatus utilizes driven opposed rolls to withdraw the web from the supply roll and to advance the leading section of the web onto the end of a driven conveyor which retains the section by vacuum. A cutter mechanism is driven in timed relationship to the web movement to slash the web transversely as it passes from the rolls onto the conveyor. The transverse slashing provides a serrated cut, leaving tabs which connect the leading section on the conveyor with the remainder of the web. Then, in further travel, opposed high speed rollers engage the leading section on the conveyor to tear the tabs and thus separate the leading section as a wrapper sheet of required length.

United States Patent 1191 Roberts et al. 1March 20, 1973 154] WEB FEED MECHANISM FOR 3,269,235 8/1966 Crouch et a1. ..83/152 x 7 3,399,587 9/ 1968 Lee et 31 I 3,543,980 12 1970 B k ll ..2 [75] Inventors: Franklin Roberts, Springfield; I I 25/96,

Assignee:

James S. Groom, Harnpden, both of Mass.

Package Machinery Company, East Longrneadow, Mass. 22] 'Filed: Feb. 1, 1971 21 Appl. N01; 111,281

521 U.s. c1. "225/96, 83/152; 83/306, 225/100 1 51} Int. Cl; .;....'.B26f 3/02 [58] Field of Search ....225/96, 100, 94; 83/306; 305, J 83/152 56] References Cited UNITED .STATES PATENTS 3,101,164 8/1963 Kileet al. ..225/96 X 2,639,772 7 5/1953 Sandberg' et al 225/100 X 3,285,112 11/1966 Dale etal ..83/152 2,268,190 1 12/1941 7 Copeland et a1. 225/100- 2,456,699 12/1948 l-lanson etaln 225/96 2,956,484 Subklew 25/96X Primary Examiner-Frank T. Yost Att0meyMcCormick,' Paulding & l-luber [57] ABSTRACT supply roll and to advance the leading section of the web onto the end of a driven conveyor which retains the section by vacuum. A cutter mechanism is driven in timed relationship to'the web movement to slash the web transversely as it passes from the rolls onto the conveyor. The transverse slashing provides aserrated cut, leaving tabs which connect the leading section on the conveyor with the remainder of the web.

Then, in further travel, opposed high speed rollers engage the leading' section on the conveyor to tear the tabs and thus separate the leading section as a l wrapper sheet .of required length.

4 Claims, 4Drawing Figures a I PATEMTEUMzoma FIG. I.

SHEET 10F 3 00 OOOOOOOOOOO OOOOOOOOOOOOO I N VEN TOR.

FRANKLIN B ROBERTS JAMES S. GROOM PATEr-mnmmm 3,721,375

SHEET 2 BF 3 WEB FEED MECHANISM FOR WRAPPING MACHINES BACKGROUND OF THE INVENTION In providing apparatus of the type herein involved wherein a web of material is fed and cut into sheets of discrete and uniform length such as may be used in a wrapping machine associated with the apparatus, difficult'y has heretofore been encountered in maintaining continuity in the advance of the web as the sheets are cut therefrom. That is, when a sheet is cut from the leading section of an advancing weband moved on toward a wrappingmachine, control is often lost for the web, and this results in faulty operation of the apparatus and in cutting sheets of uneven length,'in some cases.

SUMMARY OF THE INVENTION predetermined rate of speed and moves it onto a driven conveyor indicated generally by the number 12 which continues to advance the leading section L of the web W. The apparatus also includes a cutter mechanism.

shown generally at 14 which provides the serrated cut between the leading section L of the web on the driven conveyor means 12 and the following portion of the web W. Finally, the apparatus includes a driven speedup roller structure 16 which tears the leading section L from the remainder of the web W as a discrete sheet to be depositedupon a take-away conveyor 18 extending to a wrapping machine (not shown).

All of the aforementioned subassemblies of the apparatus are supported on a frame which includes side castings 20, 20 which are spaced apart transversely of the web W and outside its longitudinal edges and which are connected together for further support by a plurality of transversely extending crossbars of different diameter, but each of which is designated by the reference 22 for convenience. This frame structure tion of the web and is driven at a rate of speed tending to'advance the web at'a greater rate than imparted to it by. the original drive rolls or feed rolls, thus causing the leading section of the web to slip relative to the conveyor until it has been severed from the following por-- tion of the web. As the web passes between the feed rolls onto the vacuum belt conveyor, it is cut transversely in a serrated out which leaves tabs to be certain thatthe web is drawn onto the vacuum belt conveyor following the leading section defined by the serrated cut. Then, the said serrated section is separated as a sheet from the remainder of the web by high-speed rolls which engage the leading section on its opposite faces while still on the vacuum belt conveyor. These highspeed rollers engage the leading section only very briefly, but for a sufficient duration to tear the retaining tabs due to the speed-up of the leading section, thus to separate the leading section. The leading section and,

the following end of the-web remain under the speed control of the vacuum belt conveyor until the separated leading section or sheet can be removed from the conveyor and utilized in the wrapping machine.

DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT As can most clearly be seen in FIGS. 1 and 2, the apparatus provided in accordance with the present invention includes a first driven means indicated generally by the reference number 10 for engaging a web of material W and withdrawing it from a supply roll or the like (not shown). This driven means 10 advances the web W at a supports the first driven means 10 in the upper portion, the driven conveyor means 12 in an intermediate por-' tion and at an acute angle to a vertical plane, the cutter mechanism 14 being supported by the frame elements between the first driven means 10 and the conveyor;

means 12, and the second driven means-or speed-up mechanism 16 is supported to engage the leading section L of the web while on the driven conveyor means 12.

The first driven means 10 comprises three rolls 24,.

26 and 28 mounted on transversely disposed horizontal shafts extending between the upper portion of the side frame members 20, 20. The shafts 26 and 28 are driven by a common drive, a portion of which is indicated at 30 in FIG. 1, and it will be seen that the web W passes between the rolls 26 and 28, the roll 28 being located above the roll 26 and being urged by a spring 32 downwardly so that the web will be engaged between the said rolls. The drive for the rolls 26 and 28 is adapted to operate continuously to withdraw the web from its supply roll at a substantially constant predetermined rate, this being movement from left to right as viewedin FIG. 2, and to move it downwardly toward the driven conveyor 12 at the said rate. Before the apparatus is started into operation, the leading edge of the web W is fed between the rolls 26 and 28 and downwardly onto the conveyor 12, and to facilitate this initial feeding or start of the web, it is desirable to pro- 'vide a hand crank (not shown) on the shaft of one of the rolls so that the said rolls can be rotated manually. Preferably, the hand crank is located on the shaft 34 supporting the upper roll 28.

The driven conveyor subassembly 12 features the use of a pair of driven perforate endless vacuum belts 36, Q

36 (FIG. 1). Each endless belt 36 is entrained over an upper pulley 38 and a lower pulley 40 near a side frame member 20, the said pulleys being rotatably supported by a vertical frame plate 42 mounted in the frame in- A greater than the predetermined rate of advance for the web W at the first drive means.

Further,'each endless perforate belt 36 in passing from the upper pulley 38 to the bottom pulley 40 moves over an open channel member or vacuum box 50 which defines a vacuum chamber connected with a vacuum pump (not shown) whereby to draw a vacuum through the perforations in the belt 36 as it moves downwardly. The vacuum within the box 50 is controlled by a movable valve structure indicated generally at 52 which is arranged so that there will be no vacuum applied through the belt 36 as it approaches the bottom pulley 40. This permits the leading section L of the web W to curl away from the vacuum belts 36, 36 and pass on to the take-away conveyor 18 which also incorporates the use ofvacuum belts having one end entrained over suitablejpulleys on the same shaft as the bottom pulley 40 for each vacuum belt 36.

As seen in FIG. 1, the vacuum belts 36, 36 are located so that they will engage and support the web W or the leading section L thereof at its longitudinal marginal portions. As also seen in FIG. 1, the web is additionally supported by a pair of inwardly located endless belts 54, 54 which are driven at the same rate of speed as the belts 36, 36 over pulleys supported on" inner frame plates 56, 56. It will be observed in FIG. -1 that the auxiliary support belts 54 do not extend downwardly as far as the vacuum belts-36, 36. v

- Turning now to the cutter mechanism 14 as best seen in FIGS. 2 and 3, it will be noted that the said cutter mechanism includes a shearblade or knife '58 which is retained in a rotary mount 60 and a bed blade or knife 62 held in a pivotally mounted support 64. The rotary mount 60 is secured for rotation with a driven shaft 66 so that it will be rotated continuously by the common drive for the first driven means and the driven conveyor 12. The said mount is so constructed that it will carry the shear blade 58 into contact with the web W one time during each revolution of the driven shaft 66. This contact of the shear blade 58 with the web W occurs just before the web reaches the driven conveyor 12, the contact with the web being made opposite the cutting edge of the bed blade of knife 62 when the pivoted bed blade support 64 is at rest against a stop 68, this being the full line position for the said support shown in FIGS. 2 and 3. When the bed blade support 64 is in such position, the bed knife 62 will engage the inside of the web W so that the shear blade 58 will slash through the web. This transverse slashing of the web W is not complete. That is, the shear blade 58 as shown in FIG. 4 is provided with a plurality of notches 70, 70 spaced along its cutting edge 72 so that the transverse cut performed is a serrated cut, tabs being left by the said notches. The serrated cut in the web defines the leading section L of the web from the remainder thereof, the said leading section being disposed on the driven conveyor 12 but being connected to the remainder or following portion of the web by the aforementioned tabs.

Obviously, if the bed blade support 64 remains at its at rest position so that the web will be serrated during each revolution of the shearblade mount 60, the length of the leading section L of the web will be determined by the rate of rotation of the mount relative to the rate of advance of the web W. This, of course, can be adjusted by changing the gearing connecting the drive for the first driven means 10 and the drive for the driven shaft 66 upon which the shear blade mount 60 is retained.

The length of the leading section L can also be adjusted in equal increments withouta gear change by holding the bed knife 62 out of engagement with the web W for one or a selected plurality of revolutions of the rotary mount 60. That is, when the pivoted support 64 ismoved to the broken line position shown in FIG. 3, the contact of the shear blade 58 with the web W will not effect a slashing thereof. Therefore, if the pivoted support 64 is held in the broken line position for one complete revolution of the rotary mount 60 and returned to the full line position for the next revolution thereof, the leading section L will be twice the length of such section if the pivoted support was retained always at the at rest position. If the pivoted support is held in the broken line position for two revolutions of the shear blade and then returned to the full line position for the next revolution thereof, the leading section L will be three times the normal length. i

The means selectively moving the pivoted mount 64 to the aforesaid broken line position and permitting its return to the full line position comprises a cam 74 which can be axially adjustably secured to a continuously rotating cam shaft 76. The cam shaft 76 is driven by the common drive, and the cam 74 can be positioned along it selectively to be placed under the pivoted support 64 so as to engage it and pivot it to the broken line position about its mounting on one of the transverse bars 22. When the cam 74 is displaced from association with the support 64, the said support will rest against the stop 68. It will also rest against the stop 68 once during each revolution of the cam 74 when associated with the support. 1

Turning now to the second driven means 16 and with particular reference to FIGS. 1 and 2, it will be seen that this includes two pairs of driven rollers, one pair being located inside of each of the vacuum belts 36, 36

I and each such pair comprising a large roller 78 and a smaller roller 80. Each large roller 78 is located adjacent the inside surface of the leading section L of the web W on the driven conveyor means 12, the said large roller of each pair being mounted for rotation on a shaft 82. Each small roller 80 of a pair is mounted on a shaft 84 for rotation therewith adjacent the outside surface of the leading section L. The shaft 82 is driven from the common drive, and by means of gearing 86 (FIG. 1) it drives the shaft 84, the drive arrangements being such that the peripheral speed of the rollers 78 and 80 in each pair is greater than the rate of advance of the web W, preferably at the surface speed of the driven conveyor belts 36, 36.

While the bearing 86 a the ends of the shafts 82 and 84 remains engaged for continuous rotation of the rollers 78 and 80, the shaft 84 is supported in spaced apart arms 88, 88 which pivots the shaft 84 outwardly so that the rollers 80, 80 will not engage the leading section L of the web with the associated rollers 78, 78 during a major portion of the time. That is, the arms 88, 88 are fixed to a pivot shaft 90 which at one end has a cam follower arm 92 (FIG. 1) secured to it for operation by a cam (not shown) on the cam shaft 76. This means that for each revolution of a cam shaft 76, during which time the bed blade support 64 will be dropped to the full line position for onecut of the web defining the leading section L, the cam on the shaft 76 will operate the follower arm 92 to pivot the pivot shaft 90 in a clockwise direction as viewed in FIG. 2 andthus to bring the rollers 80, 80 into engagement with the lead ing section L against the larger rollers 78, 78. The cam to be transferred to the take-away conveyor '18' leading to the wrapping machine.

We claim: 1 1.. Apparatus for feeding a web of material and separating it into sheets for a wrapping machine or thelike comprising a first driven means engaging the web to withdraw it from a supply roll or the like to advance it at a predetermined rate, a driven conveyor means spaced from said first means and arranged to receive and convey the leading section of the advancing web, a cutter mechanism disposed between said first means and said conveyor means to intermittently engage and slash the advancing web transversely thereof except for spaced apart tabs which connect the leading section of the web on the conveyor means tothe following portion of the web, said cutter mechanism comprising a bed blade mounted in a pivoted support on one side of the web and transversely thereof, a shear blade retained in a rotary mount on the other side of the web,

drive'means for the cutter mechanism operable in timed relationship with said first means'and conveyor means to rotate said shear blade mount and to move said bed blade toward and away from the web so that said shear bladeand bed blade cooperate to slash said web onlyonce duringa selected number of revolutions of the shear blade mount, and second driven means supported for movement into brief engagement with the leading section of the web on the conveyor means, said second driven means tending to advance said leading section at a speed greater than said rate, whereby to tear said tabs and separate said leading section from the web as a wrapper sheet.

2. The apparatus of claim 1 wherein said first driven means comprisesa pair of opposed rolls which engage the web therebetween, and said conveyor means comprises at least one endless perforate belt through which a vacuum is drawn to retain and convey the leading section of the web on said belt.

3. The apparatus of claim 1 wherein said first driven means comprises a pair of opposed rolls which engage the web therebetween, and said second driven means comprises at least one pair of opposed rollers driven at a higher peripheral speed than said opposed rolls, at least one of said rollers in a pair being movable relative to the other and to the leading section of the web and .movable toward said other roller to engage the said leading section briefly between the rollers in a pair.

4. The apparatus of claim 1 wherein said first driven means comprises a pair of opposed rolls which engage the web therebetween, said driven conveyor means comprises a plurality of transversely spaced endless perforate belts throu h which a vacuum is drawn to retain the leading sec on of the web on .the belts, and

said second driven means comprises a pluralityof pairs of opposed rollers which are spaced'transversely in pairs, each pair being driven at a higher peripheral speed than said rolls, at least one roller in each pair being movable relative to the other and to theleading section of the web, all of said one rollers in the pairs 1 being-movable together toward the other rollers to en-' gage the leading section of the web briefly but simul taneouslybetween the rollers in the pairs. 

1. Apparatus for feeding a web of material and separating it into sheets for a wrapping machine or the like comprising a first driven means engaging the web to withdraw it from a supply roll or the like to advance it at a predetermined rate, a driven conveyor means spaced from said first means and arranged to receive and convey the leading section of the advancing web, a cutter mechanism disposed between said first means and said conveyor means to intermittently engage and slash the advancing web transversely thereof except for spaced apart tabs which connect the leading section of the web on the conveyor means to the following portion of the web, said cutter mechanism comprising a bed blade mounted in a pivoted support on one side of the web and transversely thereof, a shear blade retained in a rotary mount on the other side of the web, drive means for the cutter mechanism operable in timed relationship with said first means and conveyor means to rotate said shear blade mount and to move said bed blade toward and away from the web so that said shear blade and bed blade cooperate to slash said web only once during a selected number of revolutions of the shear blade mount, and second driven means supported for movement into brief engagement with the leading section of the web on the conveyor means, said second driven means tending to advance said leading section at a speed greater than said rate, whereby to tear said tabs and separate said leading section from the web as a wrapper sheet.
 2. The apparatus of claim 1 wherein said first driven means comprises a pair of opposed rolls which engage the web therebetween, and said conveyor means comprises at least one endless perforate belt through which a vacuum is drawn to retain and convey the leading section of the web on said belt.
 3. The apparatus of claim 1 wherein said first driven means comprises a pair of opposed rolls which engage the web therebetween, and said second driven means comprises at least one pair of opposed rollers driven at a higher peripheral speed than said opposed rolls, at least one of said rollers in a pair being movable relative to the other and to the leading section of the web and movable toward said other roller to engage the said leading section briefly between the rollers in a pair.
 4. The apparatus of claim 1 wherein said first driven means comprises a pair of opposed rolls which engage the web therebetween, said driven conveyor means comprises a plurality of transversely spaced endless perforate belts through which a vacuum is drawn to retain the leading section of the web on the belts, and said second driven means comprises a plurality of pairs of opposed rollers which are spaced transversely in pairs, each pair being driven at a higher peripheral speed than said rolls, at least one roller in each pair being movable relative to the other and to the leading section of the web, all of said one rollers in the pairs being movable together toward the other rollers to engage the leading section of the web briefly but simultaneously between the rollers in the pairs. 